ZCZC SPCSWOMCD ALL ACUS11 KWNS 261808 SPC MCD 261808 MIZ000-OHZ000-INZ000-262045- Mesoscale Discussion 0307 NWS Storm Prediction Center Norman OK 0108 PM CDT Tue Mar 26 2024 Areas affected...much of lower Michigan...northeastern Indiana...northwestern Ohio Concerning...Severe potential...Watch unlikely Valid 261808Z - 262045Z Probability of Watch Issuance...20 percent SUMMARY...An increasingly organized band of showers, and developing thunderstorms, may be accompanied by increasing potential for strong to locally severe surface gusts by 4-5 PM EDT. It is still not clear that a severe weather watch is needed, but trends are being monitored for this possibility. DISCUSSION...Weak destabilization within a narrow pre-frontal corridor of low-level warming and moistening, coupled with large-scale ascent aided by warm advection, has contributed to increasing showers across western lower Michigan southward toward the Indianapolis IN vicinity. Some lightning has recently been noted southeast of South Bend, but low-level lapse rates are still relatively modest and the moistening is only contributing to very weak CAPE. This may be slow to improve, but breaks in cloud cover may allow for at least some continuing insolation during the next few hours. Perhaps more notably, within the left exit region of an intensifying mid-level jet (in excess of 100 kt around 500 mb) nosing north-northeastward through the lower Ohio Valley, strengthening low-level frontogenetic forcing is forecast along the eastward advancing front across central lower Michigan through the Indiana/Ohio border area by 20-21Z. This may support a consolidating and deepening band of convection with increasing potential to produce lightning. In the presence of fairly strong (and strongly sheared) south-southwesterly lower/mid-tropospheric flow (including 40-50+ kt mean ambient flow in the lowest 3-6 km AGL), activity may become increasingly organized. Downward mixing of momentum may contribute to potentially damaging wind gusts reaching the surface in northeastward surging segments, while the line advances eastward toward the lower Great Lakes region through late afternoon. ..Kerr/Hart.. 03/26/2024 ...Please see www.spc.noaa.gov for graphic product... ATTN...WFO...CLE...ILN...DTX...APX...IWX...GRR... LAT...LON 40428544 42978529 44938539 44928356 43948281 41398341 40408392 40428544 NNNN